// Emacs style mode select	 -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//		Handling interactions (i.e., collisions).
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: p_inter.c,v 1.4 1997/02/03 22:45:11 b1 Exp $";


// Data.
#include "doomdef.h"
#include "dstrings.h"
#include "sounds.h"

#include "doomstat.h"

#include "m_random.h"
#include "i_system.h"

#include "am_map.h"

#include "p_local.h"

#include "s_sound.h"

#ifdef __GNUG__
#pragma implementation "p_inter.h"
#endif
#include "p_inter.h"


#define BONUSADD		6




// a weapon is found with two clip loads,
// a big item has five clip loads
int		maxammo[NUMAMMO] = {200, 50, 300, 50};
int		clipammo[NUMAMMO] = {10, 4, 20, 1};


//
// GET STUFF
//

//
// P_GiveAmmo
// Num is the number of clip loads,
// not the individual count (0= 1/2 clip).
// Returns false if the ammo can't be picked up at all
//

boolean
P_GiveAmmo
( player_t*		player,
  ammotype_t	ammo,
  int			num )
{
    int			oldammo;

    if (ammo == am_noammo)
        return false;

    if (ammo < 0 || ammo > NUMAMMO)
        I_Error ("P_GiveAmmo: bad type %i", ammo);

    if ( player->ammo[ammo] == player->maxammo[ammo]  )
        return false;

    if (num)
        num *= clipammo[ammo];
    else
        num = clipammo[ammo]/2;

    if (gameskill == sk_baby
            || gameskill == sk_nightmare)
    {
        // give double ammo in trainer mode,
        // you'll need in nightmare
        num <<= 1;
    }


    oldammo = player->ammo[ammo];
    player->ammo[ammo] += num;

    if (player->ammo[ammo] > player->maxammo[ammo])
        player->ammo[ammo] = player->maxammo[ammo];

    // If non zero ammo,
    // don't change up weapons,
    // player was lower on purpose.
    if (oldammo)
        return true;

    // We were down to zero,
    // so select a new weapon.
    // Preferences are not user selectable.
    switch (ammo)
    {
        case am_clip:
            if (player->readyweapon == wp_fist)
            {
                if (player->weaponowned[wp_chaingun])
                    player->pendingweapon = wp_chaingun;
                else
                    player->pendingweapon = wp_pistol;
            }
            break;

        case am_shell:
            if (player->readyweapon == wp_fist
                    || player->readyweapon == wp_pistol)
            {
                if (player->weaponowned[wp_shotgun])
                    player->pendingweapon = wp_shotgun;
            }
            break;

        case am_cell:
            if (player->readyweapon == wp_fist
                    || player->readyweapon == wp_pistol)
            {
                if (player->weaponowned[wp_plasma])
                    player->pendingweapon = wp_plasma;
            }
            break;

        case am_misl:
            if (player->readyweapon == wp_fist)
            {
                if (player->weaponowned[wp_missile])
                    player->pendingweapon = wp_missile;
            }
        default:
            break;
    }

    return true;
}


//
// P_GiveWeapon
// The weapon name may have a MF_DROPPED flag ored in.
//
boolean
P_GiveWeapon
( player_t*		player,
  weapontype_t	weapon,
  boolean		dropped )
{
    boolean		gaveammo;
    boolean		gaveweapon;

    if (netgame
            && (deathmatch!=2)
            && !dropped )
    {
        // leave placed weapons forever on net games
        if (player->weaponowned[weapon])
            return false;

        player->bonuscount += BONUSADD;
        player->weaponowned[weapon] = true;

        if (deathmatch)
            P_GiveAmmo (player, weaponinfo[weapon].ammo, 5);
        else
            P_GiveAmmo (player, weaponinfo[weapon].ammo, 2);
        player->pendingweapon = weapon;

        if (player == &players[consoleplayer])
            S_StartSound (NULL, sfx_wpnup);
        return false;
    }

    if (weaponinfo[weapon].ammo != am_noammo)
    {
        // give one clip with a dropped weapon,
        // two clips with a found weapon
        if (dropped)
            gaveammo = P_GiveAmmo (player, weaponinfo[weapon].ammo, 1);
        else
            gaveammo = P_GiveAmmo (player, weaponinfo[weapon].ammo, 2);
    }
    else
        gaveammo = false;

    if (player->weaponowned[weapon])
        gaveweapon = false;
    else
    {
        gaveweapon = true;
        player->weaponowned[weapon] = true;
        player->pendingweapon = weapon;
    }

    return (gaveweapon || gaveammo);
}



//
// P_GiveBody
// Returns false if the body isn't needed at all
//
boolean
P_GiveBody
( player_t*		player,
  int			num )
{
    if (player->health >= MAXHEALTH)
        return false;

    player->health += num;
    if (player->health > MAXHEALTH)
        player->health = MAXHEALTH;
    player->mo->health = player->health;

    return true;
}



//
// P_GiveArmor
// Returns false if the armor is worse
// than the current armor.
//
boolean
P_GiveArmor
( player_t*		player,
  int			armortype )
{
    int			hits;

    hits = armortype*100;
    if (player->armorpoints >= hits)
        return false;	// don't pick up

    player->armortype = armortype;
    player->armorpoints = hits;

    return true;
}



//
// P_GiveCard
//
void
P_GiveCard
( player_t*		player,
  card_t		card )
{
    if (player->cards[card])
        return;

    player->bonuscount = BONUSADD;
    player->cards[card] = 1;
}


//
// P_GivePower
//
boolean
P_GivePower
( player_t*		player,
  int /*powertype_t*/	power )
{
    if (power == pw_invulnerability)
    {
        player->powers[power] = INVULNTICS;
        return true;
    }

    if (power == pw_invisibility)
    {
        player->powers[power] = INVISTICS;
        player->mo->flags |= MF_SHADOW;
        return true;
    }

    if (power == pw_infrared)
    {
        player->powers[power] = INFRATICS;
        return true;
    }

    if (power == pw_ironfeet)
    {
        player->powers[power] = IRONTICS;
        return true;
    }

    if (power == pw_strength)
    {
        P_GiveBody (player, 100);
        player->powers[power] = 1;
        return true;
    }

    if (player->powers[power])
        return false;	// already got it

    player->powers[power] = 1;
    return true;
}



//
// P_TouchSpecialThing
//
void
P_TouchSpecialThing
( mobj_t*		special,
  mobj_t*		toucher )
{
    player_t*	player;
    int			i;
    fixed_t		delta;
    int			sound;

    delta = special->z - toucher->z;

    if (delta > toucher->height
            || delta < -8*FRACUNIT)
    {
        // out of reach
        return;
    }


    sound = sfx_itemup;
    player = toucher->player;

    // Dead thing touching.
    // Can happen with a sliding player corpse.
    if (toucher->health <= 0)
        return;

    // Identify by sprite.
    switch (special->sprite)
    {
        // armor
        case SPR_ARM1:
            if (!P_GiveArmor (player, 1))
                return;
            player->message = GOTARMOR;
            break;

        case SPR_ARM2:
            if (!P_GiveArmor (player, 2))
                return;
            player->message = GOTMEGA;
            break;

        // bonus items
        case SPR_BON1:
            player->health++;				// can go over 100%
            if (player->health > 200)
                player->health = 200;
            player->mo->health = player->health;
            player->message = GOTHTHBONUS;
            break;

        case SPR_BON2:
            player->armorpoints++;			// can go over 100%
            if (player->armorpoints > 200)
                player->armorpoints = 200;
            if (!player->armortype)
                player->armortype = 1;
            player->message = GOTARMBONUS;
            break;

        case SPR_SOUL:
            player->health += 100;
            if (player->health > 200)
                player->health = 200;
            player->mo->health = player->health;
            player->message = GOTSUPER;
            sound = sfx_getpow;
            break;

        case SPR_MEGA:
            if (gamemode != commercial)
                return;
            player->health = 200;
            player->mo->health = player->health;
            P_GiveArmor (player,2);
            player->message = GOTMSPHERE;
            sound = sfx_getpow;
            break;

        // cards
        // leave cards for everyone
        case SPR_BKEY:
            if (!player->cards[it_bluecard])
                player->message = GOTBLUECARD;
            P_GiveCard (player, it_bluecard);
            if (!netgame)
                break;
            return;

        case SPR_YKEY:
            if (!player->cards[it_yellowcard])
                player->message = GOTYELWCARD;
            P_GiveCard (player, it_yellowcard);
            if (!netgame)
                break;
            return;

        case SPR_RKEY:
            if (!player->cards[it_redcard])
                player->message = GOTREDCARD;
            P_GiveCard (player, it_redcard);
            if (!netgame)
                break;
            return;

        case SPR_BSKU:
            if (!player->cards[it_blueskull])
                player->message = GOTBLUESKUL;
            P_GiveCard (player, it_blueskull);
            if (!netgame)
                break;
            return;

        case SPR_YSKU:
            if (!player->cards[it_yellowskull])
                player->message = GOTYELWSKUL;
            P_GiveCard (player, it_yellowskull);
            if (!netgame)
                break;
            return;

        case SPR_RSKU:
            if (!player->cards[it_redskull])
                player->message = GOTREDSKULL;
            P_GiveCard (player, it_redskull);
            if (!netgame)
                break;
            return;

        // medikits, heals
        case SPR_STIM:
            if (!P_GiveBody (player, 10))
                return;
            player->message = GOTSTIM;
            break;

        case SPR_MEDI:
            if (!P_GiveBody (player, 25))
                return;

            if (player->health < 25)
                player->message = GOTMEDINEED;
            else
                player->message = GOTMEDIKIT;
            break;


        // power ups
        case SPR_PINV:
            if (!P_GivePower (player, pw_invulnerability))
                return;
            player->message = GOTINVUL;
            sound = sfx_getpow;
            break;

        case SPR_PSTR:
            if (!P_GivePower (player, pw_strength))
                return;
            player->message = GOTBERSERK;
            if (player->readyweapon != wp_fist)
                player->pendingweapon = wp_fist;
            sound = sfx_getpow;
            break;

        case SPR_PINS:
            if (!P_GivePower (player, pw_invisibility))
                return;
            player->message = GOTINVIS;
            sound = sfx_getpow;
            break;

        case SPR_SUIT:
            if (!P_GivePower (player, pw_ironfeet))
                return;
            player->message = GOTSUIT;
            sound = sfx_getpow;
            break;

        case SPR_PMAP:
            if (!P_GivePower (player, pw_allmap))
                return;
            player->message = GOTMAP;
            sound = sfx_getpow;
            break;

        case SPR_PVIS:
            if (!P_GivePower (player, pw_infrared))
                return;
            player->message = GOTVISOR;
            sound = sfx_getpow;
            break;

        // ammo
        case SPR_CLIP:
            if (special->flags & MF_DROPPED)
            {
                if (!P_GiveAmmo (player,am_clip,0))
                    return;
            }
            else
            {
                if (!P_GiveAmmo (player,am_clip,1))
                    return;
            }
            player->message = GOTCLIP;
            break;

        case SPR_AMMO:
            if (!P_GiveAmmo (player, am_clip,5))
                return;
            player->message = GOTCLIPBOX;
            break;

        case SPR_ROCK:
            if (!P_GiveAmmo (player, am_misl,1))
                return;
            player->message = GOTROCKET;
            break;

        case SPR_BROK:
            if (!P_GiveAmmo (player, am_misl,5))
                return;
            player->message = GOTROCKBOX;
            break;

        case SPR_CELL:
            if (!P_GiveAmmo (player, am_cell,1))
                return;
            player->message = GOTCELL;
            break;

        case SPR_CELP:
            if (!P_GiveAmmo (player, am_cell,5))
                return;
            player->message = GOTCELLBOX;
            break;

        case SPR_SHEL:
            if (!P_GiveAmmo (player, am_shell,1))
                return;
            player->message = GOTSHELLS;
            break;

        case SPR_SBOX:
            if (!P_GiveAmmo (player, am_shell,5))
                return;
            player->message = GOTSHELLBOX;
            break;

        case SPR_BPAK:
            if (!player->backpack)
            {
                for (i=0 ; i<NUMAMMO ; i++)
                    player->maxammo[i] *= 2;
                player->backpack = true;
            }
            for (i=0 ; i<NUMAMMO ; i++)
                P_GiveAmmo (player, i, 1);
            player->message = GOTBACKPACK;
            break;

        // weapons
        case SPR_BFUG:
            if (!P_GiveWeapon (player, wp_bfg, false) )
                return;
            player->message = GOTBFG9000;
            sound = sfx_wpnup;
            break;

        case SPR_MGUN:
            if (!P_GiveWeapon (player, wp_chaingun, special->flags&MF_DROPPED) )
                return;
            player->message = GOTCHAINGUN;
            sound = sfx_wpnup;
            break;

        case SPR_CSAW:
            if (!P_GiveWeapon (player, wp_chainsaw, false) )
                return;
            player->message = GOTCHAINSAW;
            sound = sfx_wpnup;
            break;

        case SPR_LAUN:
            if (!P_GiveWeapon (player, wp_missile, false) )
                return;
            player->message = GOTLAUNCHER;
            sound = sfx_wpnup;
            break;

        case SPR_PLAS:
            if (!P_GiveWeapon (player, wp_plasma, false) )
                return;
            player->message = GOTPLASMA;
            sound = sfx_wpnup;
            break;

        case SPR_SHOT:
            if (!P_GiveWeapon (player, wp_shotgun, special->flags&MF_DROPPED ) )
                return;
            player->message = GOTSHOTGUN;
            sound = sfx_wpnup;
            break;

        case SPR_SGN2:
            if (!P_GiveWeapon (player, wp_supershotgun, special->flags&MF_DROPPED ) )
                return;
            player->message = GOTSHOTGUN2;
            sound = sfx_wpnup;
            break;

        default:
            I_Error ("P_SpecialThing: Unknown gettable thing");
    }

    if (special->flags & MF_COUNTITEM)
        player->itemcount++;
    P_RemoveMobj (special);
    player->bonuscount += BONUSADD;
    if (player == &players[consoleplayer])
        S_StartSound (NULL, sound);
}


//
// KillMobj
//
void
P_KillMobj
( mobj_t*		source,
  mobj_t*		target )
{
    mobjtype_t	item;
    mobj_t*		mo;

    target->flags &= ~(MF_SHOOTABLE|MF_FLOAT|MF_SKULLFLY);

    if (target->type != MT_SKULL)
        target->flags &= ~MF_NOGRAVITY;

    target->flags |= MF_CORPSE|MF_DROPOFF;
    target->height >>= 2;

    if (source && source->player)
    {
        // count for intermission
        if (target->flags & MF_COUNTKILL)
            source->player->killcount++;

        if (target->player)
            source->player->frags[target->player-players]++;
    }
    else if (!netgame && (target->flags & MF_COUNTKILL) )
    {
        // count all monster deaths,
        // even those caused by other monsters
        players[0].killcount++;
    }

    if (target->player)
    {
        // count environment kills against you
        if (!source)
            target->player->frags[target->player-players]++;

        target->flags &= ~MF_SOLID;
        target->player->playerstate = PST_DEAD;
        P_DropWeapon (target->player);

        if (target->player == &players[consoleplayer]
                && automapactive)
        {
            // don't die in auto map,
            // switch view prior to dying
            AM_Stop ();
        }

    }

    if (target->health < -target->info->spawnhealth
            && target->info->xdeathstate)
    {
        P_SetMobjState (target, target->info->xdeathstate);
    }
    else
        P_SetMobjState (target, target->info->deathstate);
    target->tics -= P_Random()&3;

    if (target->tics < 1)
        target->tics = 1;

    //	I_StartSound (&actor->r, actor->info->deathsound);


    // Drop stuff.
    // This determines the kind of object spawned
    // during the death frame of a thing.
    switch (target->type)
    {
        case MT_WOLFSS:
        case MT_POSSESSED:
            item = MT_CLIP;
            break;

        case MT_SHOTGUY:
            item = MT_SHOTGUN;
            break;

        case MT_CHAINGUY:
            item = MT_CHAINGUN;
            break;

        default:
            return;
    }

    mo = P_SpawnMobj (target->x,target->y,ONFLOORZ, item);
    mo->flags |= MF_DROPPED;	// special versions of items
}




//
// P_DamageMobj
// Damages both enemies and players
// "inflictor" is the thing that caused the damage
//	creature or missile, can be NULL (slime, etc)
// "source" is the thing to target after taking damage
//	creature or NULL
// Source and inflictor are the same for melee attacks.
// Source can be NULL for slime, barrel explosions
// and other environmental stuff.
//
void
P_DamageMobj
( mobj_t*		target,
  mobj_t*		inflictor,
  mobj_t*		source,
  int			damage )
{
    unsigned	ang;
    int			saved;
    player_t*	player;
    fixed_t		thrust;
    int			temp;

    if ( !(target->flags & MF_SHOOTABLE) )
        return; // shouldn't happen...

    if (target->health <= 0)
        return;

    if ( target->flags & MF_SKULLFLY )
    {
        target->momx = target->momy = target->momz = 0;
    }

    player = target->player;
    if (player && gameskill == sk_baby)
        damage >>= 1;	// take half damage in trainer mode


    // Some close combat weapons should not
    // inflict thrust and push the victim out of reach,
    // thus kick away unless using the chainsaw.
    if (inflictor
            && !(target->flags & MF_NOCLIP)
            && (!source
                || !source->player
                || source->player->readyweapon != wp_chainsaw))
    {
        ang = R_PointToAngle2 ( inflictor->x,
                                inflictor->y,
                                target->x,
                                target->y);

        thrust = damage*(FRACUNIT>>3)*100/target->info->mass;

        // make fall forwards sometimes
        if ( damage < 40
                && damage > target->health
                && target->z - inflictor->z > 64*FRACUNIT
                && (P_Random ()&1) )
        {
            ang += ANG180;
            thrust *= 4;
        }

        ang >>= ANGLETOFINESHIFT;
        target->momx += FixedMul (thrust, finecosine[ang]);
        target->momy += FixedMul (thrust, finesine[ang]);
    }

    // player specific
    if (player)
    {
        // end of game hell hack
        if (target->subsector->sector->special == 11
                && damage >= target->health)
        {
            damage = target->health - 1;
        }


        // Below certain threshold,
        // ignore damage in GOD mode, or with INVUL power.
        if ( damage < 1000
                && ( (player->cheats&CF_GODMODE)
                     || player->powers[pw_invulnerability] ) )
        {
            return;
        }

        if (player->armortype)
        {
            if (player->armortype == 1)
                saved = damage/3;
            else
                saved = damage/2;

            if (player->armorpoints <= saved)
            {
                // armor is used up
                saved = player->armorpoints;
                player->armortype = 0;
            }
            player->armorpoints -= saved;
            damage -= saved;
        }
        player->health -= damage;		// mirror mobj health here for Dave
        if (player->health < 0)
            player->health = 0;

        player->attacker = source;
        player->damagecount += damage;	// add damage after armor / invuln

        if (player->damagecount > 100)
            player->damagecount = 100;	// teleport stomp does 10k points...

        temp = damage < 100 ? damage : 100;

        if (player == &players[consoleplayer])
            I_Tactile (40,10,40+temp*2);
    }

    // do the damage
    target->health -= damage;
    if (target->health <= 0)
    {
        P_KillMobj (source, target);
        return;
    }

    if ( (P_Random () < target->info->painchance)
            && !(target->flags&MF_SKULLFLY) )
    {
        target->flags |= MF_JUSTHIT;	// fight back!

        P_SetMobjState (target, target->info->painstate);
    }

    target->reactiontime = 0;			// we're awake now...

    if ( (!target->threshold || target->type == MT_VILE)
            && source && source != target
            && source->type != MT_VILE)
    {
        // if not intent on another player,
        // chase after this one
        target->target = source;
        target->threshold = BASETHRESHOLD;
        if (target->state == &states[target->info->spawnstate]
                && target->info->seestate != S_NULL)
            P_SetMobjState (target, target->info->seestate);
    }

}

